#include <iostream>
#include "gurobi_c++.h"

using namespace std;

int main() {
	
	//8. Exception Handling
	try {
		//1.1 Basic elements declaration
		GRBEnv env = GRBEnv();
		GRBModel model= GRBModel(env);

		//1.2 Parameters definition
		const int N = 2;  //number of resources  
		const int M = 2; //number of products (D.V.)
		int a[N][M]= {{1, 2},
					  {4, 3}}; //coefficients in the constraints
		int b[N] = {40, 120};   //coefficients of the RHS (Right-Hand-Side)
		int c[M] = {40, 50};    //coefficients of objective function  


		//2. Decision Variables 
		GRBVar x1, x2;	
		x1= model.addVar(0.0, GRB_INFINITY, 0.0, GRB_CONTINUOUS);
		x2 = model.addVar(0.0, GRB_INFINITY, 0.0, GRB_CONTINUOUS);

		//3. Integrate variables into model 
		model.update(); 	

		//4. Constraint Declaration 
		model.addConstr(1*x1 + 2*x2 <= 40);       
		model.addConstr(4*x1 + 3*x2 <= 120);

		//5. set the model to maximization
		model.set(GRB_IntAttr_ModelSense, -1); 
		model.setObjective(40*x1+50*x2);


		//6. Optimize the model
		model.optimize();

		//7.1 Check Optimality  
		int status = model.get(GRB_IntAttr_Status);
		if (status == GRB_OPTIMAL) {
			
			//7.2 Output the objective value and solutions
			double ObjValue = model.get(GRB_DoubleAttr_ObjVal);
			cout<<"total cost= "<<ObjValue<<endl;

			cout<<"x1  ="<<x1.get(GRB_DoubleAttr_X)<<endl;
			cout<<"x2  ="<<x2.get(GRB_DoubleAttr_X)<<endl;

		}
		else if (status == GRB_INF_OR_UNBD) {
			cout << "The model cannot be solved because it is infeasible or unbounded" << endl;
		}
		else if(status == GRB_INFEASIBLE) {
			cout << "The model cannot be solved because it is infeasible" << endl;
		}
		else if(status == GRB_UNBOUNDED) {
			cout << "The model cannot be solved because it is unbounded" << endl;
		}
		else {
			cout << "Optimization was stopped with status" << status << endl;
		}

	} catch(GRBException e) {
		cout << "Error code = " << e.getErrorCode() << endl;
		cout << e.getMessage() << endl;

	} catch(...) {
		cout << "Exception during optimization" << endl;

	}

	getchar();
	return 1;
}